class Solution5 {
    public int lengthOfLongestSubstring(String s) {
         int len = s.length();
         int max = 0 ; 
         int[] hash = new int[128] ;
         char[] arr = s.toCharArray() ;
         for(int i=0 , j=0 ; i<len && j<len ; j ++){
              hash[arr[j]]++ ;
              while(hash[arr[j]] > 1){
                hash[arr[i++]] -- ; 
              }
              max = Math.max(max , j-i+1);
         }
         Long a = new Long(10) ;
         Integer b = new Integer(20);
         if(a> b){
             System.out.println();
         }
         return max ;
    }
}